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GH-44125: [Python] Add concat_batches function (#44126)

### Rationale for this change

Allows to concatenate recordbatches in Python

### What changes are included in this PR?

Adds `concat_batches` function and tests

### Are these changes tested?

yes

### Are there any user-facing changes?

A new public function has been added
* GitHub Issue: #44125

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Co-authored-by: Joris Van den Bossche <jorisvandenbossche@gmail.com>